503 research outputs found
A Market-Based Approach to Manage Endangered Species Interactions
An economic activity interacts with an endangered species. The activity can be divided into mutually exclusive strata with different levels of interaction. Observing the activity in order to monitor interactions is costly. It may be desirable to manage the activity with a probability model which balances the benefit from the activity against the cost of the interaction with the endangered specie instead. The model gives rise to a permit scheme which fixates the risk of interaction over all strata and which uses the market mechanism to optimally allocate the activity between strata. The model can facilitate uncertainty in interaction rate estimates.Endangered species interactions; permit scheme; probability model
The Premium of Marine Protected Areas: A Simple Valuation Model
The article addresses the induced cost, the premium, from establishing a marine protected area in a deterministic model of a fishery. Outside the protected area, the fishery is managed optimally through total allowable catch quotas. The premium is found to be increasing and convex along the protection parameter. Biological measures are introduced to increase the understanding of the mechanisms in the bioeconomic system. Time-series solutions show that the net return per unit of fish increases after the protected area is established.Bioeconomics, dynamic programming, fisheries management, marine protected areas, migration, modeling, optimization, renewable resources., International Development, International Relations/Trade, Political Economy, Research and Development/Tech Change/Emerging Technologies, C61, Q22, Q57.,
Prevalence and trends in screen time from 2014-2019, among Norwegian adolescents
Master's thesis in Public health science (ME516
Ecological Risk Factors and Cumulative Risk for Intimate Partner Violence; Evidence from CMI Project 'Women in the Developmental State: Female Employment and Empowerment in Ethiopia'
Postponed access: the file will be accessible after 2023-11-21This high prevalence of intimate partner violence (IPV) against Ethiopian women is a concern from a human rights and development perspective. For targeted prevention programmes to be implemented, it is crucial to understand the risk factors for IPV. Previous studies have researched how personal history, micro-, exo-, and macrosystem level factors are associated with IPV. However, few studies have researched all the four ecological levels simultaneously, and how risk factors associate cumulatively with IPV.Master's Thesis in Global DevelopmentGLODE33
Postprocessing of Non-Conservative Flux for Compatibility with Transport in Heterogeneous Media
A conservative flux postprocessing algorithm is presented for both
steady-state and dynamic flow models. The postprocessed flux is shown to have
the same convergence order as the original flux. An arbitrary flux
approximation is projected into a conservative subspace by adding a piecewise
constant correction that is minimized in a weighted norm. The application
of a weighted norm appears to yield better results for heterogeneous media than
the standard norm which has been considered in earlier works. We also
study the effect of different flux calculations on the domain boundary. In
particular we consider the continuous Galerkin finite element method for
solving Darcy flow and couple it with a discontinuous Galerkin finite element
method for an advective transport problem.Comment: 34 pages, 17 figures, 11 table
Isogeometric analysis applied to frictionless large deformation elastoplastic contact
This paper focuses on the application of isogeometric analysis to model frictionless large deformation contact between deformable bodies and rigid surfaces that may be represented by analytical functions. The contact constraints are satisfied exactly with the augmented Lagrangian method, and treated with a mortar-based approach combined with a simplified integration method to avoid segmentation of the contact surfaces. The spatial discretization of the deformable body is performed with NURBS and C0-continuous Lagrange polynomial elements. The numerical examples demonstrate that isogeometric surface discretization delivers more accurate and robust predictions of the response compared to Lagrange discretizations
Spatial management of a fishery under parameter uncertainty
Spatial management of a fishery under parameter uncertainty is analyzed. The habitat is divided into two areas, and the effort level in the two areas may be different. The migration of biomass between the areas follows a diffusion process; two different specifications are considered. The model features logistic growth and Schaefer production functions. The intrinsic growth rate is treated as uncertain; the uncertainty is symmetric
and spatially homogeneous. It is found that the optimal, spatial distribution
of effort with respect to expected harvest is neither homogeneous or heterogeneous
everywhere, but homogenous for a given subset of the parameter space and heterogeneous elsewhere
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